Key fob pianofortes



L. H. BROWNE. KEY FOR PIANOFORTES.

No. 32,972. Patented Augrfi, 1861.

UNITED STATES PATENT orricn LOUIS H. BROWNE, OF BOSTON, MASSACHUSETTS.

KEY FOR PIANOFORTES.

Specification of Letters Patent No. 32,972, dated August 6, 1861.

To all whom "it may concern:

Be it known that I, LOUIS H. BROWNE, of Boston, in the county of Suffolkand State of Massachusetts, have made a new and useful improvement inthe manufacture of keys for pianofortes, organs, melodeons, and allother musical instruments wiere similar keys are or can be used by acombination of porcelain and wood instead of ivory and wood ormother-of-pearl and wood, as now commonly in use; and that the followingdescription, taken in connection with the accompanying drawings,hereinafter referred to, forms a full and correct specification of thesame. Further, that I have therein set forth the nature and principlesof my said improvement, by means whereof the same may be distinguishedfrom anything designed to serve the same purpose and now commonly used,together with such parts as I claim and desire to secure by LettersPatent.

The drawing, Figure l, is a top view of the keys of a piano-forte orother instrument where similar keys are used; a represent ing theporcelain part now substituted by me for ivory or mother-of-pearl; and brepresenting the ebony keys, one octave only being shown. The drawing, F2, represents the front end of a white key, the upper surface of whichis slightly curved. The drawing, Fig. 3, is a sectional view of theporcelain key, across.

To enable others skilled in the art to make and use my improvedmanufacture, I will proceed to describe my manner of making andperfecting the same. It is first molded in steel molds, the materialbeing subjected to a heavy pressure to make it compact. The obverse orfinger side is made slightly curved, as in Fig. 2. Greater accuracy andcertainty in the manufacture of the same from porcelain material is thussecured, by forming, as it wer, a longitudinal rib or back-bone in thecenter; thus obviating in a great degree the otherwise inevitablespringing, warping, or twisting, of the keys into short bends or twists,during the process of baking and enameling. The greater quantity is alsoserviceable in the middle because in the biscuit it absorbs more of themoisture in the enamel, and by that means precipitates more of theenamel on to the middle than upon the edges; and the heat in theenamel-kiln produces a lateralflow, thus obviating the slightly-apparentcavities, depressions, or inequalities, usually found upon a planesurface of porcelain, ceramic, or fictile, manufacture.

The front end of each key describes a segment of a circle, or othercurve, which shape serves to compensate the unequal shrinkage incidentto all articles of porcelain materials in the baking and enameling. Yvcre this shape not adopted, the slightest deviation from a straight linein front would render the keys entirely useless for the purposedesigned.

is the keys warp and become uneven to a greater or less extent on thesurface, they are straightened in manner as follows: Either before orafter the enameling process they are introduced into a muffle or ovenopen at the mouth and inserted in a reverberating furnace, where theyremain until they have attained a degree of heat that will render themsu'tliciently ductile to yield to a pressure applied by weights to bringthe tops to a level, and levers and cams to straighten the sides andsquare the back ends.

I polish the enamel in manner hereinafter set forth, thereby beingenabled to give to porcelain an appearance superior to that of ivory,and a feel highly grateful to the touch. I pass them under or overrevolving wheels or blocks charged with pulverized stone, knowngenerally as either Arkansas, Turkey, or Hindoostan oil-stone, in water.The effect of the contact and attrition is to take off the bright andglossy appearance, and the feel peculiar to all articles of thefire-enamel finish, which would otherwise render the keysill-calculated, if not entirely useless for the purpose intended, by thepresence of a hard, cold feeling and a too-dazzling appearance.

What I claim as my invention. and desire to have secured to me byLetters Patent, is only as follows The manner or process ofstraightening the porcelain as hereinbefore set forth.

In testimony that the foregoing is a correct specification, I havehereunto set my signature, this 30th day of December A. D. l 58.

LOUIS H. BROWNE. In presence of- A. M. fvfCPIL-UL, J11, LUTHER BLoDcETT.

